POS0267 OUTCOMES DURING AND AFTER LONG-TERM TOCILIZUMAB TREATMENT IN PATIENTS WITH GIANT CELL ARTERITIS
Authors: M. Matza, N. Dagincourt, S. Mohan, A. Pavlov, J. Han, J. H. Stone, S. Unizony
Journal: Annals of the Rheumatic Diseases (2022)

Background Data on the long-term efficacy and safety of tocilizumab (TCZ) for giant cell arteritis (GCA), including incidence and timing of disease relapse after TCZ discontinuation, is limited. Objectives We aimed to evaluate the long-term outcomes of GCA patients treated with TCZ in a real-world setting. Methods Retrospective analysis of GCA patients treated with TCZ for &gt;9 months at a single center between 2010-2021. Time to relapse and annualized relapse rate during and after TCZ treatment, prednisone use and safety were assessed. Relapse was defined as the re-appearance of clinical manifestations of GCA that required treatment intensification regardless of the erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) levels. The duration of TCZ treatment was determined as per the best clinical judgement of the treating rheumatologist. Results A total of 57 GCA patients were followed for a mean (SD) period of 3.4 (1.7) years. Baseline characteristics and treatments received are shown in Table 1. Patients were maintained on their initial TCZ course for a mean (SD) period of 2.0 (1.3) years. The initial TCZ course lasted &gt;12 months in 50 (88%) patients. During the initial TCZ course, 8 (14.0%) patients relapsed. Kaplan-Meier (KM) estimated relapse rates on TCZ were 10.5% and 14.9% at 12 and 18 months, respectively (Figure 1 A ). TCZ was discontinued due to long-term remission in 37 (64.9%) patients and after an adverse event in 6 (10.5%) patients. Of the 43 patients stopping TCZ due to remission or adverse event, 19 (44.2%) subsequently relapsed. KM estimated relapse rates after TCZ discontinuation were 30.4% and 44.0% at 12 and 18 months, respectively (Figure 1 B ). Overall, 12 patients received more than one TCZ course. The aggregation of all TCZ courses (mean 2.5 years) and all periods off TCZ following the initial TCZ treatment (mean 0.9 years) showed that 11 (19.3%) patients relapsed while on TCZ and 20 (35.1%) patients relapsed during time off TCZ. An analysis adjusting for age, sex, prednisone dose at initiation of first TCZ course, and disease type (new onset vs. relapsing) at initiation of first TCZ course showed an annualized relapse rate (95% CI) of 0.1 (0.0-0.2) during TCZ treatment and 0.4 (0.3-0.7) off TCZ (rate ratio 0.2, p&lt;0.0001). By the end of follow up, 42 (73.7%) patients were able to wean off prednisone. During the study, 12 serious adverse events occurred in 11 (19.3%) patients. Among those 12 events, 3 (25%) were related or possibly related to TCZ exclusively (i.e., soft tissue infection, bacteremia, and COVID-19), 3 (25%) to prednisone exclusively (i.e., osteoporotic fracture, diabetic ketoacidosis and stroke), and 2 (16.7%) to either TCZ or prednisone (i.e., pneumonia and sepsis). Table 1. Baseline characteristics and treatments GCA patients(n = 57) Age, mean (SD) 70.1 (9.3) Female sex 39 (68.4) New onset disease at TCZ initiation 18 (31.6) Initial TCZ treatment 4 mg/Kg intravenously monthly 2 (3.5) 8 mg/Kg intravenously monthly 13 (22.8) 162 mg subcutaneously every 2 weeks 6 (10.5) 162 mg subcutaneously weekly 36 (63.2) On prednisone at TCZ initiation 57 (100) Prednisone dose (mg) at TCZ initiation, mean (SD) 32.3 (21.7) Patients receiving &gt;1 TCZ course 12 (21.1) Duration of initial TCZ course (years), mean (SD) 2.0 (1.3) Total duration of TCZ treatment (years), mean (SD) 2.5 (1.6)* Values represent number and (%) unless otherwise specified. *Aggregated time on tocilizumab (TCZ) for those patients that received more than 1 TCZ course. GCA, giant cell arteritis; SD, standard deviation. Conclusion Long-term TCZ treatment was efficacious in maintaining disease remission and sparing the use of prednisone in patients with GCA. Over 40% of patients stopping TCZ after long-term remission or adverse event relapsed following TCZ discontinuation. Acknowledgements This study was sponsored by Genentech, Inc. Disclosure of Interests Mark Matza: None declared, Nicholas Dagincourt Employee of: Working for Genentech, Inc., as employees of Everest Clinical Research, Shalini Mohan Shareholder of: Genentech, Inc., Employee of: Genentech, Inc., Andrey Pavlov Employee of: Working for Genentech, Inc. as an employee of Everest Clinical Research, Jian Han Shareholder of: Genentech, Inc., Employee of: Genentech, Inc., John H. Stone Consultant of: Roche, Grant/research support from: Roche, Sebastian Unizony Grant/research support from: Research funding from Genentech, Inc.